• 제목/요약/키워드: thermoelectric.

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Enhancing the Thermoelectric Properties of Layered Bi2O2Q (Q = S, Se): the Effect of Mixed Chalcogen Net

  • Lee, Wang Ro;Lee, Changhoon
    • Journal of the Korean Physical Society
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    • 제73권11호
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    • pp.1684-1690
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    • 2018
  • The layered semiconductors $Bi_2O_2Q$ (Q = S, Se) consists of $Bi_2O_2$ layers sandwiched by Q square nets. On the basis of density functional theory calculations, we examined the thermoelectric properties of $Bi_2O_2S$, $Bi_2O_2Se$ as well as hypothetical structure of $Bi_2O_2$($S_{0.5}Se_{0.5}$) consisting of mixed chalcogen nets. The thermoelectric power factor of $Bi_2O_2S_{0.5}Se_{0.5}$ is much greater than those of $Bi_2O_2S$ and $Bi_2O_2Se$, suggesting that introducing mixed chalcogen net in $Bi_2O_2Q$ is a possible way of enhancing the thermoelectric property of $Bi_2O_2Q$.

Development of A Floating Solar Thermoelectric Generator Using A Dome Shaped Fresnel Lens for Ocean Application

  • Seong-Hoon Kim;Jeung-Sang Go
    • 한국산업융합학회 논문집
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    • 제26권6_1호
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    • pp.1001-1010
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    • 2023
  • To solve the problem that photovoltaic panels can not harvest electrical energy at a cloudy day and night, a floating solar thermoelectric generator (FSTEG, hereafter) is studied. The FSTEG is consisted of a dome shaped Fresnel lens to condense solar energy, a thermoelectric module connected with a heat sink to keep temperature difference, a floating system simulating a wavy ocean and an electrical circuit for energy storage. The dome shaped Fresnel lens was designed to have 29 prisms and its optical performance was evaluated outdoors under natural sunlight. Four thermoelectric modules were electrically connected and its performance was evaluated. The generated energy w as stored in a Li-ion battery by using a DC-DC step-up converter. For the application of ocean environment, the FSTEG was covered by the dome shaped Fresnel lens and sealed to float in a water-filled reservoir. The harvested energy shows a potential and a method that the FSTEG is suitable for the energy generation in the ocean environment.

온도차 및 부하 저항에 따른 열전모듈의 발전 특성 분석 (Experimental Study on the Power Generation of a Thermoelectric Module with Temperature Difference and Load Resistance)

  • 이공훈;김욱중;고득용
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.1942-1947
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    • 2007
  • A thermoelectric module can be used for cooling or power generation. The basic requirements to achieve a significant thermoelectric performance are the same for both generators and coolers. Thermoelectric modules with $Bi_2Te_3$ materials are usually employed in the cooling applications below room temperature but it can also be used for the power generation in the similar temperature range. In the present study, the power generation with a $Bi_2Te_3$ thermoelectric module has been investigated. The temperature difference between the hot and cold sides of the module is maintained with electric heater and cold water from the circulating water bath. The result shows that the electric current generated increases with temperature difference and decreases with the load resistance. However, the voltage increases with both the temperature difference and load resistance. The electric power increases with temperature difference and it has the maximum value when the load resistance is about 4 ${\Omega}$ for a given device.

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열전소자를 이용한 정밀 항온 유지 장치에 관한 실험 및 시뮬레이션 연구 (A study on a precision temperature control unit using thermoelectirc module)

  • 박경서;송영중;임홍재;장시열;이기성;정재일;신동훈
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.1937-1941
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    • 2007
  • During a process of a nanoimprint for manufacturing LCD, a small temperature variation on the LCD glass can cause thermal stress and generate unexpected displacement. To avoid this trouble, a precision temperature control unit using thermoelectric modules is appropriate for nanoimprint processes. The unit consists of an air control system, a cooling water control system, and a power control system. The air control system includes a thermoelectric module, thermocouples measuring temperatures of air and a duct-stale fin, and two air fans. The heat generated by the thermoelectric module is absorbed by the cooling water control system. The power control system catches the temperature of the thermoelectric module, and a PID controller with SCR controls the input power of the thermoelectric module. Temperature control performance is evaluated by experiment and simulation. The temperature control unit is able to control the exit temperature about ${\pm}2^{\circ}C$ from the incoming fluid temperature, and the error range is ${\pm}0.1^{\circ}C$. However, the control time is approximately 30minute, which needs further study of active control

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체온 이용이 가능한 나노입자 박막 열전소자의 플랫폼 개발연구 (Design of the Platform for a Nanoparticle thin Film Thermoelectric Device transforming Body Heat into Electricity)

  • 양승건;조경아;최진용;김상식
    • 전기전자학회논문지
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    • 제20권2호
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    • pp.174-176
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    • 2016
  • 본 연구에서는 HgTe 나노입자 박막 수평열전 플랫폼에 via를 형성하여 나노입자 박막 양단의 온도 차이를 극대화하였다. HgTe 나노입자 박막은 p-type의 열전 특성을 보였으며, HgTe 나노입자 박막 수평열전소자에서 제백계수는 $290{\mu}V/K$이였다. 또한 피부 위의 via 열전 플랫폼을 통해서 향후 차세대 웨어러블 전자 소자의 구현 가능성을 확인하였다.

볼밀링한 Bi-Te-Sb계 분말의 열전특성에 관한 연구 (Thermoelectric Property of Ball Milled Bi-Te-Sb Powder)

  • 유지훈;배승철;하국현;김병기;이길근
    • 한국분말재료학회지
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    • 제12권6호
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    • pp.387-392
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    • 2005
  • The p-type semiconductor $Bi_2Te_3-Sb_2Te_3$ thermoelectric materials were fabricated by melting, milling and sintering process and their thermoelectric properties were characterized. The compound materials were ball-milled with milling time and the powders were sintered by spark plasma sintering process. The ball milled powders had equiaxial shape and approedmately $1\~3{\mu}m$ in size. The figure of meritz of sintered thermoelectric materials decreased with milling time because of lowered electrical resistivity. The thermoelectric properties of $Bi_2Te_3-Sb_2Te_3$ materials have been discussed in terms of electrical property with ball mill process.

열전소자의 열적조건 변화에 따른 발전 특성 (Performance of Thermoelectric Power Generator with Various Thermal Conditions)

  • 한훈식;김명기;엄석기;김서영
    • 설비공학논문집
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    • 제22권3호
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    • pp.165-170
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    • 2010
  • Experiments have been performed to investigate the key parameters determining the performance of thermoelectric power generation. The experimental results obtained show that the power output significantly increases with the temperature difference between cold and hot sides of thermoelectric generator. However, the effect of the hot side temperature under the identical temperature difference on the overall performance of a thermoelectric generator is meager. The conversion efficiency defined as the ratio of the power generated to the heat absorbed at the hot side increases with the temperature difference. The behavior of the thermoelectric generator is shown to be consistent with the theoretical analysis. The optimum current giving the maximum conversion efficiency and the maximum conversion efficiency are linearly increased with the temperature difference.

공랭식 열교환핀이 부착된 열전모듈의 냉각 성능에 관한 연구 (Cooling Performance of Thermoelectric Module with Air-Cooled Heat Exchanger Fins)

  • 신재훈;한훈식;김윤호;김서영;현재민
    • 설비공학논문집
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    • 제22권3호
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    • pp.171-179
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    • 2010
  • Thermal performance of louver fin and plate fin in a thermoelectric cooling system with a duct-flow type fan arrangement is analytically evaluated. The thermoelectric cooling system consists of a thermoelectric module and two heat exchanger fins. The analytic results show that the optimized louver fin has lower thermal resistance than plate fin. The COP and heat absorbed rate of the thermoelectric cooling system with optimized louver fins are 10.3% and 5.8% higher than optimized plate fins, respectively.

Recent Advances in Thermoelectric Power Generation Technology

  • Sharma, Ashutosh;Lee, Jun Hyeong;Kim, Kyung Heum;Jung, Jae Pil
    • 마이크로전자및패키징학회지
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    • 제24권1호
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    • pp.9-16
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    • 2017
  • Thermoelectric power generation (TEG) technology with high figure of merit (ZT) has become the need of the modern world. TEG is a potent technology which can tackle most of the environmental issues such as global warming, change in climatic conditions over the globe, and for burning out of various resources of non-renewable energy like as petroleum deposits and gasolines. Although thermoelectric materials generally convert the heat energy from wastes to electricity according to the theories Seebeck and Peltier effects yet they have not been fully exploited to realize their potential. Researchers are focusing mainly on how to improve the current ZT value from 1 to 2 or even 3 by various approaches. However, a higher ZT value is found to be difficult due to complex thermoelectric properties of materials. Hence, there is a need for developing materials with high figure of merit. Recently, various nanotechnological approaches have been incorporated to improve the thermoelectric properties of materials. In this review paper, the authors have performed a thorough literature survey of various kinds of TEG technology.

Effects of Hydrogen Reduction in Microstructure, Mechanical and Thermoelectric Properties of Gas Atomized n-type Bi2Te2.7 Se0.3 Material

  • Rimal, Pradip;Yoon, Sang-Min;Kim, Eun-Bin;Lee, Chul-Hee;Hong, Soon-Jik
    • 한국분말재료학회지
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    • 제23권2호
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    • pp.126-131
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    • 2016
  • The recent rise in applications of thermoelectric materials has attracted interest in studies toward the fabrication of thermoelectric materials using mass production techniques. In this study, we successfully fabricate n-type $Bi_2Te_{2.7}Se_{0.3}$ material by a combination of mass production powder metallurgy techniques, gas atomization, and spark plasma sintering. In addition, to examine the effects of hydrogen reduction in the microstructure, the thermoelectric and mechanical properties are measured and analyzed. Here, almost 60% of the oxygen content of the powder are eliminated after hydrogen reduction for 4 h at $360^{\circ}C$. Micrographs of the powder show that the reduced powder had a comparatively clean surface and larger grain sizes than unreduced powder. The density of the consolidated bulk using as-atomized powder and reduced atomized powder exceeds 99%. The thermoelectric power factor of the sample prepared by reduction of powder is 20% better than that of the sample prepared using unreduced powder.